How the quantum realm will go beyond computing

Over the last half-decade, quantum computing has attracted tremendous media attention. Why?

After all, we have computers already, which have been around since the 1940s. Is the interest because of the use cases? Better AI? Faster and more accurate pricing for financial services firms and hedge funds? Better medicines once quantum computers get a thousand times bigger?

Making currently intractable problems — those that are not impossible to solve but just not yet solvable with today’s technology — is fundamentally why we care about quantum.

Over time, we expect quantum computers to be in the cloud and at the edge. Their use will be invisible to most users, but the value they provide will benefit many.

The fascination of the “quantum realm”

I think the word “quantum” is a big part of the allure of this new kind of computing. Some of you may remember the television show Quantum Leap starring Scott Bakula from around 1990. Twenty-five years later, we got the first Ant-Man movie with Paul Rudd. These stories introduced us to the “quantum realm.” All fiction, but fun.

Therefore, it’s no surprise that talk of “superposition,” “entanglement” and “spooky action” attracts attention. Quantum computing is based on quantum mechanics, one of the weirdest and most surprising aspects of physics, if not all of science. Talk of “quantum” pulls people in, and they want to learn more. It almost sells itself.

If computing were all we could do with this quantum business, it would be worthwhile, but there are many more areas in which it plays a role. You, for example. Quantum mechanics describes the behavior of the smallest particles of matter, including atoms, electrons and photons. Quantum rules much of everything in and around you.

If you have ever had a knee or shoulder injury, you may have gotten an MRI so medical staff could determine the exact problem. MRI stands for “magnetic resonance imaging” and works by detecting energy released by hydrogen atoms under the influence of strong magnetic fields and radio waves. Luckily, the human body has many hydrogen atoms in water and fat, so MRI can produce high-resolution images of the areas of concern. This is a quantum process, and the application dates to the work of Felix Bloch and others starting in the 1940s.

Note my use of “high-resolution.” Since quantum science deals with the very small, we can obtain fine-grained information and details if we can use it well. In some cases, it may be the best way we can hope to measure.

A sea change in positioning

Here’s another example, although it is not quantum to start. In the old days of wooden ships, it was challenging to determine your location at sea. Latitude was relatively easy to find because of the position of stars and planets, but the earth’s rotation made longitude much trickier. Recall that if you look at a globe, the longitudinal lines go north and south, and the latitudinal ones go east and west.

One way to find your position and navigate was “dead reckoning.” Suppose you accurately knew your initial location. Then you started moving in a particular direction and speed. That is, you sailed with a given velocity. After a given amount of time, you could calculate your new position.

In this simple model, we assume that your direction did not change. This assumption is somewhat suspect because the wind blew you along, but let’s go with it. Your compass could establish your direction and changes to it.

Speed and elapsed time were more complex. One way to measure your speed was to throw a log on a rope into the water from the front of the ship and then measure how long it took to get to the back. Since you knew the ship’s length, you could calculate your speed. Aside from the measurement coarseness of watching a log move in the water, accurate timekeeping was critical for accuracy.

From clocks to GPS

It wasn’t until the 18^th century that John Harrison invented a clock so accurate it allowed sailors to measure their position precisely enough to avoid unintentionally ending up on the rocks or being hundreds of miles off course. The story of the development of this “marine chronometer” is well told in the book Longitude by Dava Sobel. It’s a saga not just of technology but of intrigue, politics and questionable competitive behavior.

Time showed up in two places in dead reckoning: once to measure the speed, then again to measure the longer elapsed time of a trip segment. In practice, any trip involved many segments as the ship tacked and jibed back and forth.

This development was not just convenient; it saved lives and revolutionized travel by sea.

Now we have GPS, so the problem is solved.

Not quite.

GPS: A panacea?

GPS, or the Global Positioning System, is a system of more than 30 satellites that send signals to devices such as your smartphone. If your phone picks up four or more of these signals, it can determine your position within a few meters or yards. You may be familiar with “triangulation,” or the more appropriate term “trilateration,” to calculate location. Instead of needing three sources, we need four or more for accuracy because of the earth’s curvature and altitude.

GPS works well with mapping software, although the GPS signals can be affected by weather and other atmospheric conditions. More significant problems, especially for those concerned with security, are “GPS jamming” or “denial,” where a signal is turned into noise, or “GPS spoofing,” where a valid signal is replaced by a stronger but wrong one. You don’t want to be on a plane that thinks it is hundreds of kilometers or miles away from its actual location.

A web search will help you find examples of each used in war zones or by domestic security forces. Denial or spoofing of GPS in a major city could snarl much of its transportation, with implications for safety and commerce.

Aside from positioning and navigation, GPS has another vital function: time.

GPS and time synchronization

If you’ve been to an ATM recently, look at your receipt. The time stamp probably came from data from GPS. Have you listened to a weather report and wondered about the accuracy of the prediction? The synchronization of the times at the distributed weather stations likely came from GPS.

Financial transactions across networks often get their time stamps from GPS. Accuracy is essential in high-speed financial applications to know the exact sequence of transactions.

Cellular base stations may use GPS to synchronize their times so as to use the broadband spectrum more precisely. You may have known you used GPS on your phone to drive to the pizza parlor for a pick-up, but GPS was also involved when you called them to place your order. If GPS fails when you are en route, several features of your phone could stop working until they resynchronize with the satellites.

Power networks are complicated these days, with multiple energy sources and often, bidirectional flow. Time synchronization from GPS is used in some grids to optimize and balance electricity distribution.

Humans lived without GPS and accurate timekeeping for thousands of years, but we have become dependent on both in our modern lives. As a thought experiment, what would your day be like without GPS?

Quantum clocks, sensors, gyroscopes and more

It turns out we can, and likely will, migrate to quantum-based solutions for PNT — positioning, navigation, and timing. The military and defense may use these solutions at first, but as with GPS, businesses can commercialize them, and we could use them in our everyday lives.

Quantum atomic clocks are used today in GPS satellites, and will eventually become pervasive as they become smaller and less expensive. They will show up in our networks, cloud data centers, cell phone towers, planes and ships, as well as in our cars and phones. Not only will they operate independently or in ensembles and be highly accurate, they will maintain that accuracy for weeks or months before resynchronizing.

Quantum sensors will measure our speed and any variations with extraordinary precision, eventually replacing the inexpensive but not very accurate accelerometers in our phones and other devices. Quantum gyroscopes will finely determine any changes in our angular movement in three dimensions, yaw, roll and pitch.

Fascinating capabilities to come

Remember that ship tacking and jibing with the wind? The computer in a self-driving car or truck will take into account the direction, slope and altitude changes of the roads. Advancing from that overboard log of hundreds of years ago, we’ll soon be able to measure all these changes hundreds of times a second.

We can even measure gravity fluctuations with a quantum gravimeter. This can determine changes in the earth’s density and help discover new resources. Other applications include safety and recovery operations, such as finding voids in collapsed buildings. We might even get early alerts for natural disasters such as landslides and sinkholes.

Like MRI, all these quantum applications have extraordinarily better resolution than the technologies they replace. MRI is often safer than previous technologies, such as x-ray. We’ve mentioned several instances in which these newer quantum measuring devices too will increase our safety.

Quantum computing is coming, and promises to make some currently intractable problems solvable. Quantum sensing and timekeeping are here today. As we drive down the costs and footprints of these devices, they will slide into our everyday lives and open up fascinating and new essential services for us all.

Bob Sutor is VP and chief quantum advocate for Infleqtion

Originally appeared on: TheSpuzz